[wingnut60]

Christal,
The mfgs seem to make a game of hiding the drain/valve on some models. Can you find the fresh tank? Somewhere below that will be a drain line with a valve on it. Look around under the trailer for a (probably) white tube--that should be the drain line. It may have a visible valve; if not, the valve is inside somewhere above where the drain line comes out.
And, as to the water sloshing out--as said, that is from a full tank sloshing around and coming out the vent line. Not a problem.